Cor Triatriatum Dexter as an Incidental Finding: Role of Two-Dimensional Transthoracic Echocardiography

Abstract

Cor triatriatum dexter (CTD) is a rare congenital cardiac anomaly in which a membranous structure divides the right atrium (RA) into two chambers. Persistence of the right valve of the sinus venosus, which usually regresses as a part of normal embryological development, is responsible for membranous partition. There is a high incidence of right-sided congenital abnormalities of the heart associated with this condition. Clinical manifestations vary depending on the degree of partitioning or septation of the RA. We present a case of CTD discovered as an incidental finding during transthoracic echocardiography and further discuss the role of two-dimensional echocardiography as a noninvasive diagnostic tool.

Cor triatriatum sinister and giant eustachian valve mimicking a tetratrial heart

“…12 Persistence of the right sinus venosus valve causes a wide Case Report range of defects, including a prominent eustachian valve, the Chiari network, and cor triatriatum dexter. 3,6 In cor triatriatum dexter, a large obstructive septum resulting from persistence of the entire right sinus venosus valve divides the right atrium into two separate chambers. The presence of significant obstruction of the venous flow should be considered mandatory for the diagnosis of cor triatriatum dexter.…”

“…In such cases, complete persistence of the right valve of the sinus venosus is responsible for the atrial division. 3 This valve usually regresses as a part of normal embryological development between 9 and 15 weeks' gestation, leaving behind remnants such as the crista terminalis superiorly and the eustachian valve of the inferior vena cava and the thebesian valve of the coronary sinus inferiorly. The severity of this defect is directly related to the degree of flow obstruction, which in turn is related to the degree of valve persistence.…”

Mind the gap: Open repair of iatrogenic cor triatriatum dexter after previous atrial septal defect repair

“…Normal embryological development involves regression of the right valve of the sinus venosus; however, failure of regression can lead to CTD with varying clinical manifestations. 1 We present a case of what we term “iatrogenic” CTD, where the RA was divided into 2 chambers from a previous atrial septal defect (ASD) repair with persistent, thickened eustachian valve (EV) leading to liver cirrhosis.…”